This invention relates in general to railroad cars and, in particular, to a coupler for rotary dump cars.
More specifically, but without restriction to the particular use which is shown and described, this invention relates to a coupler having an improved design in which bearing areas between the coupler spindle and the shank-spindle housing are increased for better strength and for minimizing stress concentrations at all bearing locations. The coupler spindle is provided with an enlarged, inboard end to cooperate with the increased size of the shank-spindle housing.
The use of a rotary dump railroad car has attracted considerable attention in recent years. Rotary dump railcars are particularly useful in unit trains which are in dedicated service delivering coal or other materials to electric power stations or other destinations. The cars may be unloaded by simply moving the train through a rotary dumper, positioning each car in the dumper, and rotating it to allow the coal to discharge. This operation is accomplished while the cars remain coupled. Because of the rotary movement of one car relative to another, the coupler is subjected to forces which would not be experienced in non-rotating designs. The coupler must be able to permit the rotation of a car with respect to the adjacent cars and resist the multiple forces encountered in use of such rotary cars.
One coupler design for connecting rotary dump cars is disclosed in U.S. Pat. No. 2,869,736 issued Jan. 20, 1959, for a Railway Coupler. Although the assembly described in U.S. Pat. No. 2,869,736 is directed to a coupler having a satisfactory design, it was found that certain improvements could be made to the structure disclosed in the patent. One shortcoming of the prior couplers, such as shown in the patent and others employed in the industry, is the inadequacy of design and a tendency to be overstressed because of undesired stress concentrations. To overcome such problems, many new designs have been introduced to better serve the railroad industry and to provide an adequate coupler for rotary conditions.
It is desirable in providing such a stronger component that it be usable without requiring substantial modifications of existing striking castings at the end of center sill and standard draft yokes which cooperate with the draft gear, a cushion unit used in each end of railcars. None of the current couplers are capable of demonstrating enhanced strength and superb characteristics with a design that can inexpensively be interchanged with conventional draft arrangements.